Suspension device for equalizing the strain on elevator cables



CABLES.

J. E. EVANS; SUSIENSION DEVICE FOR EQUALIZING THESTRAIN 0N ELEv/ITOIIOrngys,

I/ f 174g I'Illilf III/.--

Eatend-Sept 19212,

I l E, A

IIN INI Patented Sept. l2, l922.

JOSEPH E. EVANS, OF BEDFORD, INDIANA, ASSIGNOR O-F ONE-FOURTH TO OLIVERN. CLIFFORD, OF ST. LOUIS, MISSOURI, AND ONE-FOURTH TO JASPER O. G-YGER,OF

BEDFORD, INDIANA. Y

' SUSPENSION DEVICE Eon. EQUALIZING THE STRAIN oN ELEVATOE CABLES.

Application filed May 29, 1919, Serial No. 300,726. Renewed January 23,1922. Serial No. 531,314.

To all wto'm, t may concern:

Be it known that I, JosErH E. EVANS, a citizen of the United States,residing at Bedford, in the county of Lawrence and State of Indiana,have invented certain new and useful Improvements in Suspension Devicesfor Equalizin the 'VStrain on Elevator Cables, of whidli the followingis a specification.

In elevators or lifts which `are widely used for transferring passengersand freightl from one floor of a building to another, the elevator caris usually suspended from a group of cables which run over a groovedpulley at the top of the elevator shaft, the carbeing counterbalanced byweights also suspended from cables runnin over the pulley at the to ofthe shaft. ile the construction an arrangement ofthe parts of thehoisting mechanlsm varies among various manufactures of such appliances,it is in all cases usual to employ a group of several cables, generallyabout la half dozen in number to sustain the car. These cables, becauseofunavoidable variations in manu-l facture, are liable to stretchunequally, so that if they are all rigidly secured to the car they donot at all times sustain an equal load, with the result that the onewhich is the most unyielding and bears'v the greatest part of the loadis apt to break. It is the obj ect of my invention to provide'anetlicient and desirable" suspension and equalizing means intermediatethe car and the group of cables which willequalize the load between theldifferent cables and which, if any cable should break, through a defector for any other cause, will act to distribute the load equally amongthe remaining cables.

My invention consists in the novel combinaparts, the substitutionofequivalents,l and by(V variations in form and construction of.

In the drawings Fig. l is a side view of my novel equalizing device,showing associated parts of the suspension pulley,

cables and elevator car; Fig. 2 is a vertical section on the line 2 2 ofFig. 1 and on a larger scale, showing the construction of the pistonsand cylinders of the device; Fig. 3 is a horizontal section on the line3-3 of Fig. l, showing the arrangement of the equalizer bars; Fig. 4 isa fragmentary detail showing in perspective Nthe base portion of one ofthe pistons or 'plungers 5 is a front view (at right angles to theposltion of Fig. 1)', illustrating a modified form of my invention.

The same reference characters indicate the same parts in all the figuresof the drawings. Describing first the preferred form of my deviceillustrated in Figs. 1 to 4, the cables l by which the car 2 issuspended extend at the top in. a loop which passes twice over 'the topof the suspension pulley 4 at the topof the elevator shaft and oncebelow the idler pulley 5 which is arranged immediately below thesuspension pulley. '/lhe suspension pulley will thus be formed -withtwice as many grooves as the number of cables employed-in the lpresentinstance six cables being used,-andithe cables may be divided into twogroups connected respectivel to the opposite ends of a set of equalizerars 6 which are connected to the pistons or plungers of the suspensiondevice.

Broadly speaking, my device-consists of a framework secured to theelevator car and supporting and including three invertedintercommunicating oil-filled cylinders and three plungers or pistonshaving base ortions at their lower outer ends pivote to and' Fig.

equalizing bars which are connected at their opposite ends to themembers of the group of cables, which are separated into two parts. Inthe present instance the cylinder frame includes a series of guide-bolts7, eight in tor car by means of the lower portions 9, To this end a stopplate 10, orificed to engage the said reduced lower portions and seatagainst the shoulders at the end of the central portions, is provided,and also a clamping plate 11 which, by clamping nuts 12 engaging thethreaded lower end of the lower portions, may be drawn towards the plate10 topclamp the device to a suitable portion of the roof of the car, asfor instance, a pair of channel irons 13 forming a part of the frameworkof the car structure.

Thev lower head plate 14 of the cylinders 15 is orificed to engage theupper reduced portions 8 of the bolts and seat against the shoulders atthe upper end of their central portion, and a set of clamping nuts 16,cooperating with the upper threaded ends of the bolt portions 8 isemployed to clamp an upper head plate 17 against the cylinders,

' which latter seat in annular seats or recesses formed to receive themin the plates 14 and 17, and thus secure the parts together. The upperheads are formed with ports 18 affording free communication between thecyl# inders, and also with a filling orifice and a vnt, -both normallyclosed by suitable screw p ugs. A

rlhe plungers 2O are each vprovided n at the top with a pair of cupleathers 21, supported by metal cups 22, to seal the cylinder completelyand prevent the escape therefrom ofY the oil with which they are filled.The oil most suitable for use in my device is a relatively heavy mineraloil, although other varieties of oil,'or other fluids, may be employed.rlhe lower end of each piston is enlarged, as shown, and the enlargedbase 23 is grooved vertically to slidingly engage the yguide bolts 7.The bases 23 of the pistons are also slotted to each receive a pair ofthe equalizer bars 6 above mentioned, the members of each pair beingbolted or otherwise secured together so that in efiect they togetherform a single equalizer -bar having forked ends which are orificed andadapted to receive a pivot block 24 formed with gudgeons journaled inthe sides of the fork. The cables 1 are connected to the bars 6 bysocket bolts 25, the lower threaded ends of which extend throughorifices in the blocks 24 and are equipped with bearing nuts 26 and locknuts 27. Each pair of equalizer bars is pivoted to t-he base of itsassociated plunger by means of a. cross pin 28 secured againstdisplacementY by a set screw 29, and, as will be seen by reference toFig. 3, the arrangement of the slots of the bases 23 of the plungers andtheir pivotal support of the bars 6 is such that the latter have aslightly oblique and staggered arrangement, so that the cables, dividedin alternation into two groups, may exhibit no lateral pull and willtrack correctly into their respective grooves on the pulley.

- comprisin It is obvious that the strain on the two cables at oppositeends of any given pair ot bars 6 will be equal, since the downwardstress on the plunger is exerted midway between them, and this will betrue although one may have stretched so that the bars do not stand inhorizontal position. It is further obvious that since the plungers areof equal size, and the cylinders cummunicate with each other, the weightof the car will be equally distributed between the plungers, whetherthey stand at the: same or different heights in the cylinders., Theweight of the car will therefore be distributed equally among all theconnected cables. Should any cable break, the proportion and arrangementof Vthe p-arts is suc-h that the end of the pair of equalizer bars towhich it was connected will contact with the stop plate l0, and theweight of the car will be equalized between the remaining five cables.

Vhile my invention asabove explained was devised wit-h particularreference to its use as an equalizing device for the suspension ofelevator cars or lifts, it is equally applicable to the .counterb-alanceof such cars, and is also capa-ble of being used generally in anysituation when it is desirable to equalize the strain upon a group ofcables used to sustain or hoist anything in a similar manner.

In'the modification shown/ in Fig. 5, the inner guide bolts, marked 30,terminate at the level of the stop pla-te 10, which is orificed toprovide sockets which receive the lower ends of Such bolts and restrainthem against lateral movement. Preferably, the outer bolts, marked 32,are heavier and larger than the inner bolts, inasmuch as the formersustain the entire weight of the car and it is unnecessary to make theinner bolts equally heavy.

Iaclaim: v

1. A suspension device for connecting an elevator car to a group ofcables arranged to engage a supporting pulley, said device a pluralityof intercommunicating cylin ersv secured to the car, a. correspondingplurality of pistons arranged in said cylinders, and equalizing barspivotally connected at their centersto said pistons and at theiropposite ends to separate cables, said bars being arranged transverselyof a periphery of said supporting pulley.

2. A suspension device for connecting an elevator car to a group ofcables arranged to engage a supporting pulley, said device .comprising aplurality of intercommunicating cylinders, a. corresponding plurality ofpistons arranged in "said cylinders, one of said groups of cooperatingmembers being .secured to the car, and af plurality of equalizlng barsrespectively pivotally connected at their centers to the members of theother v vertical tangential plane passing through the of said groups ofcooperating members and also .connected at their opposite ends toseparate cables, said bars being arranged transversely of a verticaltangential plane passing through the periphery of said supportingpulley.

3. A suspension device according to claim 1 in which the equalizing barsare arranged obliquely with respect to a plane passlng axially throughthe cylinders and to thetangential plane passing through the peripheryof the supporting pulley, whereby the opposite cables will stand instaggered relation and track with equally spaced cables.

4. A suspension device for Iconnecting an elevator to a oup of cables,comprising a plurality of lntercommunicating cylinders secured to thecar and provided with downwardly extending guide bolts, a correspondinplurality of istons arranged in said cy inders and having their lowerends arvao ranged to slidingly engage said guide bolts, and means fo-rconnecting said cables tothe lower ends of said pistons.

5. A suspension device for connecting an elevator to a oup of cables,comprising a plurality of lntercommunicating cylinders secured to the caand provided with downwardly ektending guide bolts, a correspondingplurality ofv istons arranged in said cylinders and havingV their lowerends arranged to slidingly engage said guide bolts, and equalizing barsplvotally connected at their centers to said pistons and at theiropposite ends to separate cables.

6. A suspension device according to claim 4 in which the lower ends ofsaid pistons are enlarged and'formed with vertical grooves engaging saidguide bolts.

7. A su ension device according to claim 5 in whic the cylinders aresecu'redi to downwardly extending guide bolts and the lower ends of saidpistons are enlarged and formed with vertical grooves engaging saidguide bolts.

8. A suspensiondevice according to claim 5 in which the ends of theequal'zing bars are arranged to bring up against a stop upon the car ata fixed limit of downward movement. l

9. A suspension deviceaccording to claim 5 in which the equalizing barsare forked at their opposite ends and the forks provided with bearingsand in which pivot blocks formed with gudgeons arranged tofengage saidbearings are provided.

10. A suspension device according to claim 5 in which the equalizingbars are arranged in pairs of members secured together and spreading toform forks at the n opposite ends of a pair and in which the forks areorificed and pivot blocks formed with gudgeons arranged to engage saidoriices are provided.

1l. In adevice of the character described,

lto clamp said upper and lower plates upon said cylinder members, and aseries of plungers in said cylinders, said bolts having dependingportions'arranged to be slidingly engaged by said plungers. y

12. A plunger structure according to claim 10 in which the guide boltsare extended below the portions thereof arranged to be engaged by theplungers and are equipped with upper and lower clamping members.

13. A plunger structure according to claim 10 in which the dependinglower portions of said guide bolts are of larger diameter than the upperclamping portion and the lower head plateabuts against the an` nularshoulders at the top of such lower portions.

14. A suspension device for connecting an elevator car to a group ofcables arrangedv to engage a supporting pulley, said device `including aplurality of parallel equalizing bars respectively pivotally connectedat their centers to the car and arranged 'to 96 jointly support suchcar, said bars being connected at their opposite ends to se arate cablesand being arranged transverse y and obliquely with reference to avertical tangential plane passing through the periphery of thesupporting pulley, whereby the opposite cables will stand in staggeredrelation and track with equally spaced pulley grooves.

15. A suspension device according to claim 14 in which the equalizingbars are 105 forked at their opposite ends and the forks provided withbearings and in which pivot blocks vertically orificed for attachment tosaid cables and formed with gudgeons ar ranged to engage said bearingsare provided.

16. AV suspension device according to claim 1 4 in which the equalizingbars are forked at their opposite ends and the forks provided withbearings and in which blocks arranged to pivotally engage said bearings.are provided for attachment to said cables.

17. A suspension device according to claim 14 in which the equalizingbars are arranged in pairs of members secured together and spreading toform forks at the opposite ends of a pair and in which the members ofthe forks are oriliced and pivot blocks formed with gudgeons arranged toengage said orifices are provided.

18. In a suspension device for connecting an elevator car to a pluralityof cables, said device including an equalizing bar pivotally connectedat, its center to the car and formed with oriliced forks at its oppositeends, a'pair of pivot blocks respec- 130 tively seated in said forks andformed with gudgeons arranged to pivotally engage the orifices of saidforks. n

19. In a suspension device for con- A5 necti'ng an elevator car toy aplurality of cables, said device including an equalizing bar pivotallyconnected at its center to the car and formed with orificed forks at itsop- Lemme posite ends, a pair of pivot blocks respectively seated insaid forks and formed with gudgeons arranged to pivotally engage theorifices of said forks, said blocks being vertickalllcy orificed forattachment to a pair of ca es.

JOSEPH E. EVANS.

